A basic principle in a turbocharged engine system is that wasted energy is converted back into work. In general terms, this is achieved by harnessing the engines exhaust gases to drive a turbine wheel within a turbo housing, thus spinning a compressor wheel directly attached to the turbine by a common shaft, thereby compressing ambient air. This compressed air is delivered back into the engine's air intake system through a turbo duct, thereby delivering a greater mass of air for each intake stroke. The end effect is increased engine power output and/or fuel efficiency.
In the effort to move towards light-weight materials, automotive systems including engine systems have seen the incorporation of increased thermoplastic materials. While effective in many applications, their use in engine systems comes with certain challenges. The need to withstand increased heat and exposure to chemicals is driving the industry to explore new high performance compositions. As such, there are a growing number of engine components now being manufactured from polymeric materials.
In such systems, a known issue with thermoplastic materials is material creep. Material creep is the slow continuous deformation of a solid under the action of a constant load, and is known to be more pronounced at high temperatures. In an engine system, in particular with thermoplastic structures associated with elevated temperatures, the ability to ensure overall system integrity becomes a challenge. While the use of clamps and other connection hardware can be effectively implemented, over time the secure connections can become loose, with increased risk of system leakage and/or failure.
Having regard to air induction systems and turbo ducts in particular, the delivery of compressed air at elevated temperatures creates an overall condition that is at increased risk of system integrity failure due to material creep. In a turbo system, the inability to maintain the compressed ambient air results in a loss of power output and/or fuel efficiency, thereby negating the gains of a turbocharged system. Accordingly, there is a growing need to improve unit connectivity in thermoplastic systems such as the turbo and air induction system in automobiles.